Generally, electrical specific resistivity probing is conducted in a way of flowing a constant electric current to a conductor, measuring a potential difference of certain two points, and then calculating resistance between two points. That is to say, in order to image a geologic structure complicated with irregular media, the electrical specific resistivity probing is a geophysical method for artificially passing an electric current under the ground to measure potential differences and then monitor geological structure or anomaly.
This electrical specific resistivity probing is conducted along the ground surface and used for checking a geological structure beneath the ground surface. Also, it is one of most popular physical probing methods.
An electrical specific resistivity of a rock is varied due to the factors such as porosity of the rock, physical properties of pore water, saturation degree of fluid, kind of rock-forming minerals, existence of clay minerals, and a discontinuity dominating secondary pores (e.g., fault and fractured zone). Generally, a ground probing equipment used along the ground surface includes electrodes for transmitting or receiving underground data to/from the ground surface, a multi cable for connecting the ground surface electrodes with measurement equipment, and a measurement system.
As one of such electrical specific resistivity probing techniques, Korean Laid-open Patent Publication No. 2003-42607 discloses a ground probing technique, which is conducted in a way of inserting an electrode rod into an exploratory hole perforated in a ground probing area, and then injecting conductive cohesive solution into the ground around the electrode rod so as to improve conductive contact performance between the electrode rod and the surrounding ground.
However, this electrical specific resistivity probing method needs to perforate an exploratory hole and then install an electrode thereon, which consumes much time, human power and costs, so the conventional method is economically disadvantageous.